The field of cell replacement research and tissue engineering currently is one of the major focuses of medical technology. Cell therapy holds great promise for the future, particularly for degenerative diseases including for example heart failure, diabetes, and spinal cord injury. Loss of cells in organs with low regenerative capacity is critical to repair and recovery of function of that organ.
An exciting area of tissue engineering is the emerging technology of “self-cell” or autologous cell therapy, where cells of a given tissue type are removed from a patient, isolated, perhaps mitotically expanded and/or genetically engineered, and ultimately reintroduced into the donor/patient with or without synthetic materials or other carrier matrices. One goal of autologous cell therapy is to help guide and direct the rapid and specific repair or regeneration of tissues. Such autologous cell therapy is already a part of clinical practice; for example, using autologous bone marrow transplants for various hematologic conditions. One of the greatest advantages of autologous cell therapy over current technologies is that the autologous nature of the tissue or cell greatly reduces, if not eliminates, immunological rejection and the costs associated therewith.
In addition, allogenic cell therapy is also under investigation for tissue repair or regeneration. The term ‘allogenic cell’ refers to a cell that is isolated from a donor and transplanted into a different individual/non-donor. Allogenic cell therapy is sometimes referred to as ‘off-the-shelf’ therapy, with companies collecting cells from one or more donors, expanding the cells and packaging them for delivery to patients who were not cell donors. The issue of immunological rejection of allogenic cells can be overcome by isolating, expanding and transplanting specific cell types which have been shown to elicit little or no immune response (e.g. mesenchymal cells).
Thus, there has been interest in the delivery of cells to locations within mammalian bodies to effect new growth of tissue in the region of implantation. Various types of tissue may be implanted, including for example, bone, cartilage, muscle and other types. Similar advances are being made with other tissues such as the liver, the pancreas, tendons and ligaments. Cardiac tissue has also been the subject of cell delivery efforts in order to repair regions severely damaged by myocardial infarctions or congestive heart failure. One example of such use includes stem cells delivered surgically into the myocardium of the patient to regenerate damaged tissue, promote revascularization and angiogenesis. Desired volume concentrations of cells per delivery vary according to indications, but it is not uncommon to have tens to hundreds of millions of cells intended to be delivered to one or more sites.
However, a limitation of cell therapy, particularly within the myocardium, is lack of retention of sufficient numbers of delivered cells at the target site. The present invention is directed to a device and method for cell delivery that improves retention of the cells in the vicinity of the luminal wall.